Guttin the cat
I believe there are 2 oxygen sensors on this car, one after each cat. Both sensors are hooked into the ECU, and are used as feedback to adjust the mixture. Its been awhile since I took my combustion class, so I forget the chemical reactions that occur at the catalyst and the effect on oxygen levels if its missing(I think higher).
Anyhow, I would guess that since the front cat is no longer doing its thing, the ECU may get confused and improperly adjust the mixture. If the ECU's range of adjustment is large enough, you could end up with some bad results. If its significantly too lean, you stand a chance of frying your valves - too rich and you get deposits, etc.
Just my 2 cents.
Remember, there is no such thing as a free lunch.